Process for coating carbid with calcium cyanamid.



UNITED STATES PATENT orricn.

VITTORIO IMPERATOBI, OF ROME, ITALY, ASSIG-NOR '10 SOOIETA ITALIAN'A PERII: GARBURO DI GALCIO, OF ROME, ITALY.

rnocnss non comma CARBID WITH oALc Itrm crni rnmm.

No Drawing.

To all whom it may concern: 1

Be it known that I, Vrrronro IMPnRnToRI, a subject of the King of Italy,residing at Rome, Italy, (whose post-oflice address is Via Oondotti No.11,) have invented a certain new and useful Improvement in Proccsses forCoating Carbid with Calcium Cyanamid, of which the following is aspecification.

In the manufacture and subsequent handling of calcium carbid prior toits use for generating acetylene it is desirable owing to itshydroscopic nature to protect it from atmospheric humidity particularlythe smaller particles owing to their large surface of exposure ascompared with their small mass which accelerates decomposition. Thetpresent invention has for its principal o ject a process of treatingcalcium carbid whereby a remarkable resistance to atmospheric humidityis imparted to same. A further object of the invention is to so treatcalcium carbid that the subsequent generation of acetylene will beretarded, which feature possesses very appreciable advantages inconnection with lighting.

According to the present invention particlesofcalcium carbid while inthe presence of nitrogen are brought into contact with a heated wall,whereby the particles become coated with a thin layer of calciumcyanamid, the thickness of the coating being determined according to theduration of the reaction.

In bringing the invention means into vessels of a suitable shape andmaterial, capable of being heated to red heat or even a much highertemperature, and to the particles falling into the vessels a movement isimparted so as to brin them rapidly and uniformly into contact with theSpecification of Letters Patent. Application flled'september 14, 1912.Serial No. 720,860.

into practice I proceed as follows :-The particles of calcium carbid arecaused to fall by suitable Patented Dec. 16, 1913.

heated walls. During the heating process the carbid is kept in anatmosphere of air and pure nitrogen which may be previously heated andpreferably dried. The nitrogen reacting on the carbid may, of course, beaccompanied by other gases of a nature which will not affect the carbid.In these conditions, owin to the known reaction of nitrogen on ca c'um'carbid heated to proper temperature, on the surface of the carbidparticles, a more or less deep coating of calcium cyanamid is formedaccording to the greater or shorter duration of the reaction. Calciumcyanamid, as is known, resists at mospheric agents much better thancalcium carbid, so that the thin coating of calcium cyanamid protectsthe core of the carbid particles against the said atmospheric agents.

When the coated carbid particles are brought into contact with water,the generation of acetylene gas is complete but not so rapid as withuncoated carbid, which obviously is an appreciable advantage'in the useof calcium carbid for lighting purposes.

ters Patent of the United States is 1. A process of coating calciumcarbid with a thin layer of calcium cyanamid leaving a substantial coreof calcium carbid adapted for use in generating acetylene which consistsin bringing the particles of calcium carbid into contact with a heatedwall while in the presence of nitrogen.

2. Calcium carbid having a thin coating of calcium cyanamid for use ingenerating acetylene.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

, VITTORIO IMPERATORI. Witnesses:

Dmmo. Nannom,

NICOLA SIsro.

What I claim and desire to secure by Let-v

